ext4: Add unit test for test_free_blocks_simple

Add unit test for test_free_blocks_simple.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240103104900.464789-2-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c
index f94901fd38357ea330d39011fcc504cae0a690db..3aac42ea6a36b3721a8ea7d2855733f57463b86e 100644 (file)
--- a/fs/ext4/mballoc-test.c
+++ b/fs/ext4/mballoc-test.c
@@ -5,6 +5,7 @@
 
 #include <kunit/test.h>
 #include <kunit/static_stub.h>
+#include <linux/random.h>
 
 #include "ext4.h"
 
@@ -112,6 +113,13 @@ static void mbt_ctx_mark_used(struct super_block *sb, ext4_group_t group,
        mb_set_bits(grp_ctx->bitmap_bh.b_data, start, len);
 }
 
+static void *mbt_ctx_bitmap(struct super_block *sb, ext4_group_t group)
+{
+       struct mbt_grp_ctx *grp_ctx = MBT_GRP_CTX(sb, group);
+
+       return grp_ctx->bitmap_bh.b_data;
+}
+
 /* called after mbt_init_sb_layout */
 static int mbt_ctx_init(struct super_block *sb)
 {
@@ -297,6 +305,93 @@ static void test_new_blocks_simple(struct kunit *test)
                "unexpectedly get block when no block is available");
 }
 
+#define TEST_RANGE_COUNT 8
+
+struct test_range {
+       ext4_grpblk_t start;
+       ext4_grpblk_t len;
+};
+
+static void
+mbt_generate_test_ranges(struct super_block *sb, struct test_range *ranges,
+                        int count)
+{
+       ext4_grpblk_t start, len, max;
+       int i;
+
+       max = EXT4_CLUSTERS_PER_GROUP(sb) / count;
+       for (i = 0; i < count; i++) {
+               start = get_random_u32() % max;
+               len = get_random_u32() % max;
+               len = min(len, max - start);
+
+               ranges[i].start = start + i * max;
+               ranges[i].len = len;
+       }
+}
+
+static void
+validate_free_blocks_simple(struct kunit *test, struct super_block *sb,
+                           ext4_group_t goal_group, ext4_grpblk_t start,
+                           ext4_grpblk_t len)
+{
+       void *bitmap;
+       ext4_grpblk_t bit, max = EXT4_CLUSTERS_PER_GROUP(sb);
+       ext4_group_t i;
+
+       for (i = 0; i < ext4_get_groups_count(sb); i++) {
+               if (i == goal_group)
+                       continue;
+
+               bitmap = mbt_ctx_bitmap(sb, i);
+               bit = mb_find_next_zero_bit(bitmap, max, 0);
+               KUNIT_ASSERT_EQ_MSG(test, bit, max,
+                                   "free block on unexpected group %d", i);
+       }
+
+       bitmap = mbt_ctx_bitmap(sb, goal_group);
+       bit = mb_find_next_zero_bit(bitmap, max, 0);
+       KUNIT_ASSERT_EQ(test, bit, start);
+
+       bit = mb_find_next_bit(bitmap, max, bit + 1);
+       KUNIT_ASSERT_EQ(test, bit, start + len);
+}
+
+static void
+test_free_blocks_simple_range(struct kunit *test, ext4_group_t goal_group,
+                             ext4_grpblk_t start, ext4_grpblk_t len)
+{
+       struct super_block *sb = (struct super_block *)test->priv;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       struct inode inode = { .i_sb = sb, };
+       ext4_fsblk_t block;
+
+       if (len == 0)
+               return;
+
+       block = ext4_group_first_block_no(sb, goal_group) +
+               EXT4_C2B(sbi, start);
+       ext4_free_blocks_simple(&inode, block, len);
+       validate_free_blocks_simple(test, sb, goal_group, start, len);
+       mbt_ctx_mark_used(sb, goal_group, 0, EXT4_CLUSTERS_PER_GROUP(sb));
+}
+
+static void test_free_blocks_simple(struct kunit *test)
+{
+       struct super_block *sb = (struct super_block *)test->priv;
+       ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb);
+       ext4_group_t i;
+       struct test_range ranges[TEST_RANGE_COUNT];
+
+       for (i = 0; i < ext4_get_groups_count(sb); i++)
+               mbt_ctx_mark_used(sb, i, 0, max);
+
+       mbt_generate_test_ranges(sb, ranges, TEST_RANGE_COUNT);
+       for (i = 0; i < TEST_RANGE_COUNT; i++)
+               test_free_blocks_simple_range(test, TEST_GOAL_GROUP,
+                       ranges[i].start, ranges[i].len);
+}
+
 static const struct mbt_ext4_block_layout mbt_test_layouts[] = {
        {
                .blocksize_bits = 10,
@@ -334,6 +429,7 @@ KUNIT_ARRAY_PARAM(mbt_layouts, mbt_test_layouts, mbt_show_layout);
 
 static struct kunit_case mbt_test_cases[] = {
        KUNIT_CASE_PARAM(test_new_blocks_simple, mbt_layouts_gen_params),
+       KUNIT_CASE_PARAM(test_free_blocks_simple, mbt_layouts_gen_params),
        {}
 };